JP2024038541A - Water softening apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water softening apparatus capable of suppressing blockage of a capturing part during a regeneration process of an ion exchange resin.

SOLUTION: A water softening apparatus includes: a water softening tank in which raw water containing hardness components is softened by a weakly acidic cation exchange resin; a neutralization tank in which softened water that has passed through the water softening tank is neutralized by a weakly basic anion exchange resin; an electrolysis tank in which alkaline electrolytic water is generated; an ion concentration measuring part that measures the ion concentration of alkaline electrolytic water generated in the electrolysis tank; and a control part that controls a regeneration process which is a process of performing regeneration of the weakly basic anion exchange resin. The control part continues the regeneration process when the ion concentration measured by the ion concentration measuring part is less than a predetermined standard value, and terminates the regeneration process when the ion concentration is equal to or greater than the standard value.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a water softening device.

In conventional water softening equipment, weakly acidic cation exchange resins have hydrogen ions at the end of their functional groups and exchange hardness components (e.g., calcium ions, magnesium ions) in raw water with hydrogen ions to soften the raw water. The water is softened. As a method for regenerating a weakly acidic cation exchange resin without using salt, a method is known in which the weakly acidic cation exchange resin is regenerated using acidic electrolyzed water produced by electrolysis (see, for example, Patent Document 1).

Water softened by a weakly acidic cation exchange resin becomes acidic because hydrogen ions are released instead of hard components. In order to neutralize this, a combination of a weakly acidic cation exchange resin and a weakly basic anion exchange resin is sometimes used. As a method for regenerating weakly basic anion exchange resins, a method using alkaline electrolyzed water produced by electrolysis is known (see, for example, Patent Document 2).

Japanese Patent Application Publication No. 2011-30973 Japanese Patent Application Publication No. 2010-142674

In such water softening equipment, as the regeneration process of the weakly acidic cation exchange resin and the weakly basic anion exchange resin progresses, hardness components (e.g., calcium ions, magnesium ions, etc.) released from the weakly acidic cation exchange resin are ) increases the hardness of acidic electrolyzed water. On the other hand, anions such as carbonate ions and chloride ions are released from weakly basic anion exchange resins.

At this time, if the structure is such that part of the acidic electrolyzed water and alkaline electrolyzed water can move to each other in the electrolytic cell that generates the electrolyzed water, the hardness components will move from the acidic electrolyzed water to the alkaline electrolyzed water. . Among the hardness components transferred into the alkaline electrolyzed water, calcium ions react with carbonate ions and precipitate as calcium carbonate, and magnesium ions react with hydroxide ions in the alkaline electrolyzed water and precipitate as magnesium hydroxide. In order to remove the precipitates from the alkaline electrolyzed water so that these precipitates do not circulate within the apparatus, it is conceivable to provide a trapping section that captures the precipitates on the downstream side of the electrolytic cell.

However, due to the difference in properties between calcium carbonate and magnesium hydroxide, when the precipitated magnesium hydroxide flows into the trapping section, the trapping section becomes clogged, resulting in a significant decrease in the flow rate of alkaline electrolyzed water, and the regeneration process is completed. There was a problem that the time required for the regeneration process increased or the regeneration process could not be continued.

The present invention solves the above-mentioned conventional problems, and aims to provide a water softening device that can suppress clogging of the trapping section during the ion exchange resin regeneration process.

In order to achieve this objective, the water softening device according to the present invention includes a water softening tank that softens raw water containing hard components using a weakly acidic cation exchange resin, and a water softening tank that softens raw water containing hard components using a weakly basic cation exchange resin. A neutralization tank that neutralizes with ion exchange resin, an electrolytic tank that generates alkaline electrolyzed water, an ion concentration measuring section that measures the ion concentration of the alkaline electrolyzed water generated in the electrolytic tank, and a weak basic anion exchanger. and a control unit that controls a regeneration process that is a process of regenerating the resin, and the control unit continues the regeneration process when the ion concentration measured by the ion concentration measurement unit is less than a predetermined reference value. In the above cases, the regeneration process is ended. This achieves the intended purpose.

According to the present invention, it is possible to provide a water softening device that can suppress clogging of the trapping section during the ion exchange resin regeneration process.

FIG. 1 is a conceptual diagram showing the configuration of a water softening device according to Embodiment 1. FIG. 2 is a configuration diagram showing a water softening flow path of the water softening device according to the first embodiment. FIG. 3 is a configuration diagram showing a water softening tank regeneration circulation flow path and a neutralization tank regeneration circulation flow path of the water softening device according to the first embodiment. FIG. 4 is a diagram showing a water softening tank regeneration channel cleaning channel of the water softening device according to the first embodiment. FIG. 5 is a diagram showing a neutralization tank regeneration channel cleaning channel of the water softening device according to the first embodiment. FIG. 6 is a diagram showing a regeneration channel cleaning channel of the water softening device according to the first embodiment. FIG. 7 is a conceptual diagram showing an electrolytic cell cleaning flow path of the water softening device according to the first embodiment. FIG. 8 is a configuration diagram showing a trap cleaning channel of the water softening device according to the first embodiment. FIG. 9 is a functional block diagram of the water softening device according to the first embodiment. FIG. 10 is a configuration diagram showing a method of controlling the water softening device according to the first embodiment. FIG. 11 is a schematic diagram showing the product of alkaline electrolyzed water pH and solubility of precipitates in the water softening device according to the first embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that the following embodiments are examples of embodying the present invention, and do not limit the technical scope of the present invention. Furthermore, each figure described in the embodiments is a schematic diagram, and the ratio of the size and thickness of each component in each figure does not necessarily reflect the actual size ratio. .

(Embodiment 1)
With reference to FIG. 1, a water softening device 1 according to Embodiment 1 of the present invention will be described. FIG. 1 is a conceptual diagram showing the configuration of a water softening device 1 according to Embodiment 1 of the present invention. In addition, in FIG. 1, each element of the water softening device 1 is conceptually shown.

<Overall configuration>
The water softening device 1 is a device that generates neutral soft water from raw water containing hardness components supplied from the outside. Note that the raw water is water introduced into the apparatus from the inlet 2 (water to be treated), and is, for example, city water or well water. Raw water contains hardness components (eg calcium ions or magnesium ions). By performing water softening treatment using the water softening device 1, neutral soft water with reduced hardness can be obtained, and the soft water can be used even in areas where the hardness of raw water is high.

Specifically, as shown in FIG. 1, the water softening device 1 includes an inlet 2, a water softening tank, a neutralization tank, a water intake 7, a regenerating device 8, and a control unit 15. .

The water softener 1 also includes a drain outlet 13, a number of on-off valves (on-off valve 18, on-off valve 19, on-off valve 20, on-off valve 21, on-off valve 22, and on-off valve 23), and a number of flow path switching valves (flow path switching valves 24 to 27). These will be described in more detail below.

<Inlet and water intake>
The inlet 2 is connected to a source of raw water. The inlet 2 is an opening for introducing raw water into the water softening device 1 .

The water intake port 7 is an opening that flows through the water softening device 1 and supplies softened water to the outside of the device. The water softening device 1 can take out the water after water softening treatment from the water intake port 7 by the pressure of the raw water flowing in from the inflow port 2 .

In the water softening device 1, raw water supplied from the outside is passed through the inlet 2, the flow path 28, the first water softening tank 3, the flow path 29, the first neutralization tank 4, and the flow path during the water softening process. The water flows through the channel 30, the second soft water tank 5, the channel 31, the second neutralization tank 6, the channel 32, and the water intake port 7 in this order, and is discharged as neutral soft water.

<Soft water tank>
The water softening tanks (first water softening tank 3 and second water softening tank 5) soften raw water containing hard components by the action of a weakly acidic cation exchange resin. Specifically, water softening tanks exchange hard cations (calcium ions, magnesium ions) contained in circulating water (raw water) with hydrogen ions, which lowers the hardness of the water and softens the water. . The water softening device 1 according to the first embodiment includes a first water softening tank 3 and a second water softening tank 5 as water softening tanks.

The first water softening tank 3 softens the raw water that flows in from the inlet 2 . The first soft water tank 3 includes a flow path switching valve 24 . Details of the flow path switching valve will be described later.

The second water softening tank 5 softens water that has passed through the first neutralization tank 4, which will be described later. The second soft water tank 5 includes a flow path switching valve 26.

The first soft water tank 3 and the second soft water tank 5 are filled with a weakly acidic cation exchange resin 33.

The weakly acidic cation exchange resin 33 is an ion exchange resin having a hydrogen ion at the end of a functional group. The weakly acidic cation exchange resin 33 adsorbs cations (calcium ions, magnesium ions) that are hardness components contained in the raw water being passed through, and releases hydrogen ions. The soft water treated with the weakly acidic cation exchange resin 33 contains many hydrogen ions that have been exchanged with hardness components. That is, the soft water flowing out from the first soft water tank 3 and the second soft water tank 5 is soft water that contains many hydrogen ions and is acidified (acidic soft water).

Since the terminal of the functional group of the weakly acidic cation exchange resin 33 is a hydrogen ion, the weakly acidic cation exchange resin 33 can be regenerated using acidic electrolyzed water in the regeneration process described below. At this time, the weakly acidic cation exchange resin 33 releases cations, which are hardness components taken in during the water softening treatment.

There are no particular limitations on the weakly acidic cation exchange resin 33, and general-purpose resins can be used, such as those having a carboxyl group (-COOH) as an exchange group. Further, the hydrogen ion (H+) which is the counter ion of the carboxyl group may be a cation such as a metal ion or ammonium ion (NH4+).

<Neutralization tank>
The neutralization tanks (the first neutralization tank 4 and the second neutralization tank 6) use the action of the weakly basic anion exchange resin 34 to convert the soft water containing hydrogen ions (acidified soft water) that comes out from the water softening tank. Neutralizes the pH and makes the water neutral and soft. Specifically, since the neutralization tank adsorbs hydrogen ions and anions contained in the soft water from the water softening tank, the pH of the soft water increases and the water can be made into neutral soft water. The water softening device 1 according to the first embodiment includes a first neutralization tank 4 and a second neutralization tank 6 as neutralization tanks.

The first neutralization tank 4 neutralizes the acidic soft water that has passed through the first soft water tank 3. The first neutralization tank 4 includes a flow path switching valve 25.

The second neutralization tank 6 neutralizes the acidic soft water that has passed through the second soft water tank 5. The second neutralization tank 6 includes a flow path switching valve 27.

The first neutralization tank 4 and the second neutralization tank 6 are filled with a weakly basic anion exchange resin 34.

The weakly basic anion exchange resin 34 neutralizes hydrogen ions contained in the water that is passed through it, producing neutral water. The weakly basic anion exchange resin 34 can be regenerated using alkaline electrolyzed water in the regeneration process described below.

There are no particular limitations on the weakly basic anion exchange resin 34, and general-purpose resins can be used, such as those in a free base type.

<Playback device>
The regenerator 8 regenerates the weakly acidic cation exchange resin 33 filled in the first soft water tank 3 and the second soft water tank 5, and also regenerates the weakly acidic cation exchange resin 33 filled in the first neutralization tank 4 and the second neutralization tank 6. This is a device that regenerates the weakly basic anion exchange resin 34.

The regenerating device 8 is configured to include an electrolytic cell 9, a capturing section 10, a first water pump 11, and a second water pump 12. The regenerating device 8 includes a first supply channel 35, a second supply channel 36, a first recovery channel, and a second water softening tank 5, a second neutralization tank 6, a channel 28, and a channel 29. 37 and a second recovery channel 38 are connected to each other. Details of each channel will be described later. Note that the first supply flow path 35, the second supply flow path 36, the first recovery flow path 37, the second recovery flow path 38, the neutralization tank bypass flow path 42, and the water softener bypass flow path 44 form a soft water tank, which will be described later. A regeneration circulation flow path 39 and a neutralization tank regeneration circulation flow path 40 are formed.

<<Electrolytic cell>>
The electrolytic cell 9 electrolyzes the incoming water (water supplied from the inlet 2) using a pair of electrodes 41 (electrodes 41a and 41b) provided inside, thereby converting acidic electrolyzed water and alkaline electrolyzed water. Water is generated and discharged. More specifically, at the electrode 41a which becomes an anode during electrolysis in the regeneration process, hydrogen ions are generated by electrolysis and acidic electrolyzed water is generated. Further, in the electrode 41b which becomes a cathode during electrolysis in the regeneration process, hydroxide ions are generated by electrolysis, and alkaline electrolyzed water is generated. The electrolytic cell 9 supplies the acidic electrolyzed water to the first soft water tank 3 and the second soft water tank 5 via the first supply flow path 35 and the neutralization tank bypass flow path 42, and supplies the alkaline electrolyzed water to the second soft water tank 5. The water is supplied to the first neutralization tank 4 and the second neutralization tank 6 via the second supply channel 36 and the soft water tank bypass channel 44. Although the details will be described later, the acidic electrolyzed water produced by the electrolytic tank 9 is used to regenerate the weakly acidic cation exchange resin 33 in the first water softening tank 3 and the second water softening tank 5, and the acidic electrolyzed water produced by the electrolytic tank 9 The alkaline electrolyzed water is used to regenerate the weakly basic anion exchange resin 34 in the first neutralization tank 4 and the second neutralization tank 6. The electrolytic cell 9 is configured such that the state of energization of the pair of electrodes 41 can be controlled by a control unit 15, which will be described later.

<<Water pump>>
The first water pump 11 is a device that distributes acidic electrolyzed water to the soft water tank regeneration circulation flow path 39 (see FIG. 3) during regeneration processing by the regeneration device 8. The first water pump 11 is provided in a first recovery channel 37 that communicates and connects the first soft water tank 3 and the electrolytic tank 9. The reason for this arrangement is that the acidic electrolyzed water can be easily circulated in the water softening tank regeneration circulation channel 39 using only the first water pump 11.

The second water supply pump 12 is a device that circulates alkaline electrolyzed water through the neutralization tank regeneration circulation flow path 40 (see Figure 3). The second water supply pump 12 is provided in the second recovery flow path 38 that communicates between the first neutralization tank 4 and the electrolytic tank 9. The reason for this arrangement is that the second water supply pump 12 alone makes it easier to circulate alkaline electrolyzed water through the neutralization tank regeneration circulation flow path 40.

Further, the first water pump 11 and the second water pump 12 are communicably connected to a control unit 15, which will be described later, by wireless or wire.

<<Capturing part>>
The capture unit 10 is provided in a second supply channel 36 that connects the electrolytic cell 9 and the second neutralization tank 6 in communication.

The capture unit 10 captures precipitates contained in the alkaline electrolyzed water sent out from the electrolytic cell 9. Precipitates are reaction products produced when hardness components, which are cations released from the first water softening tank 3 and the second water softening tank 5 during regeneration treatment, react with alkaline electrolyzed water in the electrolytic cell 9. It is. More specifically, while water is electrolyzed in the electrolytic cell 9, hardness components (e.g., calcium ions, magnesium ions) released from the first water softening tank 3 and the second water softening tank 5 during the regeneration process. moves toward the cathode (electrode 41b). Since alkaline electrolyzed water is generated on the cathode side, the hardness component and alkaline electrolyzed water react to form a precipitate. For example, when the hardness component is calcium ion, when mixed with alkaline electrolyzed water, a reaction occurs that produces calcium carbonate or a reaction that produces calcium hydroxide. The precipitates derived from the hardness component are captured as precipitates by the capture section 10 provided in the second supply channel 36. By trapping the precipitates derived from the hardness component with the trapping section 10, it is possible to suppress the precipitates from flowing into the second neutralization tank 6 and accumulating. Therefore, when restarting the water softening process after the completion of the regeneration process, the precipitates accumulated in the second neutralization tank 6 react with the hydrogen ions released from the first water softening tank 3 and the second water softening tank 5. It is possible to suppress an increase in the hardness of the soft water sent out from the second neutralization tank 6 due to ionization.

In addition, during the regeneration process, the alkaline electrolyzed water in which precipitates derived from hardness components have passed through the trapping section 10 flows through the second neutralization tank 6 and the first neutralization tank 4, and then returns to the electrolytic tank 9. It is electrolyzed and used again as alkaline electrolyzed water to regenerate the weakly basic anion exchange resin 34. At this time, the hardness component contained in the acidic electrolyzed water is reduced compared to the case where the capturing section 10 is not provided. In other words, by capturing the precipitates in the capturing section 10, the hardness of the acidic electrolyzed water is reduced, so that the hard components flowing into the first soft water tank 3 and the second soft water tank 5 can be reduced, and the weakly acidic electrolyzed water can be reduced. A decrease in the regeneration efficiency of the ion exchange resin 33 can be suppressed.

Note that "the hardness components react" includes not only a state in which all the hardness components react, but also a state in which components that do not react or components whose solubility product does not exceed are included.

The trapping section 10 may have any form as long as it can separate the precipitate generated by the reaction between the hardness component and the alkaline electrolyzed water. Examples include forms using cartridge type filters, filtration layers using granular filter media, cyclone type solid-liquid separators, hollow fiber membranes, and the like.

A cartridge-type filter is a commonly used means for the capture unit 10 . As the cartridge type filter, a deep filtration type such as a thread-wound filter, a surface filtration type such as a pleated filter and a membrane filter, or a combination thereof can be used.

The trap 10 includes an on-off valve 22 and a trap drain port 14 .

The on-off valve 22 is a valve that controls drainage within the trap 10, and is provided at the bottom of the trap 10, for example. By opening the on-off valve 22, water in the trap 10 can be discharged from the trap drain 14 to the outside of the apparatus.

The trapping portion drain port 14 is an opening that drains water in the trapping portion 10 to the outside of the device. By opening the on-off valve 22 provided upstream of the trapping portion drain port 14, the water in the trapping portion 10 can be discharged from the trapping portion drain port 14 to the outside of the apparatus.

<Opening/closing valve and flow path switching valve>
A plurality of on-off valves (on-off valves 18 to 23) are provided in each flow path, and switch between an "open" state and a "closed" state in each flow path.

The plurality of on-off valves (on-off valve 18, on-off valve 19, on-off valve 21, and on-off valve 23) start or stop the flow of water to each channel by opening and closing the valves.

The on-off valve 20 and the on-off valve 22 are opened during a regeneration channel cleaning process, an electrolytic cell cleaning process, and a trapping part cleaning process, which will be described later, and discharge the regenerated circulating water to the outside of the apparatus.

A plurality of flow path switching valves (flow path switching valve 24 to flow path switching valve 27) are provided in the first soft water tank 3, the second soft water tank 5, the first neutralization tank 4, and the second neutralization tank 6, respectively. It will be done. Each of the plurality of flow path switching valves has three openings, the first opening is an inflow/outflow port that allows water to flow in and out, and the second opening does not function as an outflow port but serves as an inflow port. The third opening is an inlet that functions, and an outlet that does not function as an inlet but as an outlet. In all of the multiple flow path switching valves, the inflow and outflow ports are always "open", and depending on the direction of water flow, when either the inflow port or the outflow port is "open", the other outflow port is "open". is "closed". By providing the flow path switching valves 24 to 27, the number of on-off valves required for each flow path in the water softening device 1 can be reduced, and the cost of the water softening device 1 can be reduced.

In addition, each of the plurality of on-off valves (on-off valve 18 to on-off valve 23) and the plurality of flow path switching valves (flow path switching valve 24 to flow path switching valve 27) can communicate with the control unit 15 described below wirelessly or by wire. It is connected to the.

<Drain port>
The drain port 13 is an opening provided at the end of the drain channel 54, and is an opening for draining water inside the device to the outside of the device in the regeneration path cleaning process and the electrolytic tank cleaning process. An on-off valve 20 is provided upstream of the drain port 13, and by opening the on-off valve 20, water can be drained from the drain port 13.

<Flow path>
The bypass flow path 53 is a flow path that communicates and connects the inflow port 2 and the water intake port 7, and an on-off valve 18 is provided on the flow path. Even when performing any of the regeneration process, regeneration flow path cleaning process, electrolytic tank cleaning process, and trapping part cleaning process using the bypass flow path 53, the user of the water softening device 1 is able to drain raw water from the water intake port 7. Obtainable.

<Water softening channel>
With reference to FIG. 2, the water softening channel 43 formed during the water softening process of the water softening device 1 will be described. FIG. 2 is a configuration diagram showing the water softening channel 43 of the water softening device 1. As shown in FIG.

The water softening channel 43 (diagonal arrow in FIG. 2) is a channel for softening raw water, and the raw water flowing through the water softening channel 43 becomes neutral soft water and is discharged from the water intake port 7 to the outside of the device. Ru.

The water softening channel 43 includes an inlet 2, a channel 28, a first water softening tank 3, a channel 29, a first neutralizing tank 4, a channel 30, a second water softening tank 5, a channel 31, and a second neutralizing tank. It is formed by a tank 6, a flow path 32, and a water intake port 7.

The flow path 28 is a flow path that connects the inlet 2 to the first soft water tank 3. In other words, the flow path 28 is a flow path that guides raw water containing hardness components from the inlet 2 to the first soft water tank 3.

The flow path 29 is a flow path that connects the first soft water tank 3 to the first neutralization tank 4. That is, the flow path 29 is a flow path that guides the water softened in the first water softening tank 3 to the first neutralization tank 4.

The flow path 30 is a flow path that connects the first neutralization tank 4 to the second soft water tank 5. That is, the flow path 30 is a flow path that guides the water neutralized in the first neutralization tank 4 to the second soft water tank 5.

The flow path 31 is a flow path that connects the second soft water tank 5 to the second neutralization tank 6. That is, the flow path 31 is a flow path that guides the water softened in the second water softening tank 5 to the second neutralization tank 6.

The flow path 32 is a flow path that connects the second neutralization tank to the water intake port 7. That is, the flow path 32 is a flow path that guides the softened raw water from the second neutralization tank 6 to the water intake port 7.

As shown in FIG. 2, an on-off valve 19 is installed on the flow path 28 downstream of the inlet 2 and upstream of the first soft water tank 3. Further, an on-off valve 18 is installed in a bypass flow path 53, which will be described later. Then, by closing the on-off valve 18 and opening the on-off valve 19, the first soft water tank 3 and the inlet 2 are connected to each other. Further, the flow path switching valve 24 is switched so that the first soft water tank 3 and the first neutralization tank 4 are connected in communication, and the flow path switching valve 25 is changed so that the second soft water tank 5 and the second neutralization tank 6 are connected in communication. Switch the flow path switching valve 26 so that the first neutralization tank 4 and the second soft water tank 5 are connected to each other, and switch the flow path switching valve 27 so that the second soft water tank 5 and the second neutralization tank 6 are connected to each other. Switch to continuous connection. As a result, from the inlet 2 to the flow path 28, the first soft water tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second soft water tank 5, the flow path 31, the second neutralization tank 6, the flow A water softening channel 43 is formed which communicates and connects the channel 32 to the water intake port 7. At this time, the on-off valve 20, the on-off valve 21, and the on-off valve 23 are closed.

<Regeneration circulation channel>
Next, with reference to FIG. 3, a description will be given of the water softening tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40 that are formed during the regeneration process of the water softening device 1. FIG. 3 is a configuration diagram showing the water softening tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40 of the water softening device 1.

First, the soft water tank regeneration circulation channel 39 will be explained.

The soft water tank regeneration circulation flow path 39 is a flow path that regenerates the first soft water tank 3 and the second soft water tank 5 by flowing acidic electrolyzed water during the regeneration process, and as shown in FIG. 3 (white arrow). This is a flow path through which water sent out by the first water pump 11 flows through the electrolytic cell 9, the second soft water tank 5, and the first soft water tank 3, and returns to the electrolytic cell 9 for circulation.

Specifically, the water softening tank regeneration circulation flow path 39 includes a first supply flow path 35 connecting the electrolytic tank 9, the second water softening tank 5, the first water softening tank 3, and the first water pump 11, and a neutralization tank bypass flow. It is constituted by the channel 42 and the first recovery channel 37.

The first supply flow path 35 is a flow path that communicates and connects the downstream side of the electrolytic cell 9 to the downstream side of the second soft water tank 5, and is a flow path that supplies acidic electrolyzed water from the electrolytic cell 9 to the second soft water tank 5. It is a road.

The neutralization tank bypass flow path 42 is a flow path that bypasses the first neutralization tank 4 and communicates and connects the upstream side of the second soft water tank 5 to the downstream side of the first soft water tank 3. This is a flow path that supplies acidic electrolyzed water from 5 to the first soft water tank 3.

The first recovery flow path 37 is a flow path that communicates and connects the upstream side of the first water softening tank 3 to the electrolytic tank 9. This is a flow path for recovering water to the electrolytic cell 9. The first water pump 11 is provided in the first recovery channel 37 .

In addition, the water softener regeneration circulation flow path 39 transfers the acidic electrolyzed water sent out from the electrolyzer 9 from the downstream side of the first water softener tank 3 and the second water softener tank 5 to the first water softener tank 3 and the second water softener tank 5. This is a flow path in which the water is introduced into the water softener tank and discharged from the upstream side where a larger amount of hardness components is adsorbed than the downstream side of the water softening tank. Note that the downstream side refers to the downstream side in the flow path during water softening treatment.

Next, the neutralization tank regeneration circulation channel 40 will be explained.

The neutralization tank regeneration circulation flow path 40 is a flow path that regenerates the first neutralization tank 4 and the second neutralization tank 6 by flowing alkaline electrolyzed water during the regeneration process, and is shown in FIG. 3 (black arrow). As shown in the flow path, water sent out by the second water pump 12 flows through the electrolytic cell 9, the second neutralization cell 6, and the first neutralization cell 4, and returns to the electrolytic cell 9. be.

Specifically, the neutralization tank regeneration circulation flow path 40 includes the electrolytic tank 9, the second neutralization tank 6, the first neutralization tank 4, the second supply flow path 36 connecting the second water pump 12, and the water softening tank. It is constituted by a bypass channel 44 and a second recovery channel 38.

The second supply flow path 36 is a flow path that communicates and connects the downstream side of the electrolytic cell 9 to the downstream side of the second neutralization tank 6, and supplies alkaline electrolyzed water from the electrolytic cell 9 to the second neutralization tank 6. It is a flow path where The second supply channel 36 is provided with a trapping section 10, an on-off valve 21, an ion concentration measuring section 56, and an on-off valve 23.

The soft water tank bypass flow path 44 is a flow path that bypasses the second soft water tank 5 and communicates and connects the upstream side of the second neutralization tank 6 to the downstream side of the first neutralization tank 4. This is a flow path that supplies alkaline electrolyzed water from the tank 6 to the first neutralization tank 4.

The second recovery channel 38 is a channel that communicates and connects the upstream side of the first neutralization tank 4 to the electrolytic tank 9, and is a channel for communicating and connecting the alkaline electrolyzed water that has passed through the first neutralization tank 4 and the second neutralization tank 6. This is a flow path for recovering the electrolyte to the electrolytic cell 9. The second water pump 12 is provided in the second recovery channel 38 .

<Regeneration channel cleaning channel>
Next, with reference to FIG. 7, the regeneration channel cleaning channel 64 formed during the regeneration channel cleaning process of the water softening device 1 will be described. FIG. 7 is a configuration diagram showing the regeneration channel cleaning channel 64 of the water softening device 1. As shown in FIG.

The regeneration flow path cleaning flow path 64 allows high hardness water remaining in the flow path to be removed from the apparatus without flowing into the first neutralization tank 4 and the second neutralization tank 6 during a regeneration flow path cleaning step to be described later. This is a channel for discharging water to the The regeneration channel cleaning channel 64 is configured to include a first drainage channel 46 and a second drainage channel 47.

As shown in FIG. 7 (white arrow), the first drainage channel 46 is composed of channels connecting the inlet 2, the first water pump 11, the electrolytic cell 9, the on-off valve 20, and the drain port 13. Ru. Specifically, the first drainage flow path 46 drains the raw water flowing in from the inlet 2 through the flow path 28, the first recovery flow path 37, the first water pump 11, the electrolytic cell 9, the drainage flow path 54, and the on-off valve. 20, and the drain port 13.

The drainage channel 54 is a channel that connects to the first supply channel 35 at one end, and connects to the drain port 13 at the other end. The drainage flow path 54 is provided with an on-off valve 20. By opening the on-off valve 20, water in the flow path is drained out of the device, and by closing the on-off valve 20, water is drained from the drain port 13. Can be stopped.

As shown in FIG. 7 (black arrow), the second drainage channel 47 is a flow path that communicates and connects the inlet 2, the first soft water tank 3, the second soft water tank 5, the on-off valve 20, and the drain port 13. It is composed of roads. Specifically, the second drainage flow path 47 transfers the raw water that has flowed in from the inlet 2 to the flow path 28, the first soft water tank 3, the neutralization tank bypass flow path 42, the second soft water tank 5, and the first supply flow. The passage 35, the on-off valve 20, and the drain port 13 are flow passages in this order.

Note that it is preferable that the flow rate of water flowing through the second drainage flow path 47 is controlled to be greater than the flow rate of water flowing through the first drainage flow path. Thereby, the highly hard water in the second drainage flow path, which is a flow path including a water softening tank used during the water softening process, can be preferentially replaced with raw water. Therefore, the influence of highly hard water when starting the water softening process can be suppressed.

<Electrolytic tank cleaning channel>
Next, with reference to FIG. 7, the electrolytic cell cleaning channel 49 formed during the electrolytic cell cleaning process of the water softening device 1 will be described. FIG. 7 is a configuration diagram showing the electrolytic cell cleaning channel 49 of the water softening device 1. As shown in FIG.

The electrolytic cell cleaning channel 49 is a channel for removing precipitates caused by hardness components in the electrolytic cell 9 and in the neutralization tank regeneration circulation channel 40 during an electrolytic cell cleaning step to be described later. The electrolytic cell cleaning channel 49 is configured to include a first drainage channel 46 and a third drainage channel 50.

As shown in FIG. 7 (black arrow), the third drainage flow path 50 connects from the inlet 2 to the first soft water tank 3, the second water pump 12, the electrolytic tank 9, the on-off valve 21, the capture part 10, and the on-off valve. 22, and is constituted by each flow path that communicates with and connects the trapping part to the drainage port 14. Specifically, the third drainage flow path 50 transfers the raw water that has flowed in from the inlet 2 to the flow path 28, the first soft water tank 3, the second recovery flow path 38, the second water pump 12, the electrolytic tank 9, and the third drainage flow path 50. This is a flow path through which the second supply flow path 36, the on-off valve 21, the capture section 10, and the on-off valve 22 are passed in this order, and discharged from the capture section drain port 14 to the outside of the apparatus. More specifically, in the third drainage flow path 50, the raw water that has flowed in from the inlet 2 is made to flow into the first soft water tank 3 via the flow path 28, and is converted into acidic soft water. The generated acidic soft water is caused to flow into the electrolytic cell 9 through the second recovery flow path 38 and the second water pump 12 . Thereafter, the acidic soft water is passed through the on-off valve 21, the capture section 10, and the on-off valve 22 in this order through the second supply flow path 36 to dissolve the precipitates in the capture section 10 and exit the device from the capture section drain port 14. to be discharged.

<Catching part cleaning channel>
Next, with reference to FIG. 8, the trap cleaning channel 51 formed during the trap cleaning step of the water softening device 1 will be described. FIG. 8 is a configuration diagram showing the trap cleaning channel 51 of the water softening device 1. As shown in FIG.

The trapping portion cleaning flow path 51 is a flow path for removing precipitates derived from hardness components deposited in the trapping portion 10 during a trapping portion cleaning step to be described later. The trap cleaning channel 51 is configured to include a fourth drainage channel 52.

As shown in FIG. 8, the trap cleaning channel 51 includes, from the inlet 2, the first soft water tank 3, the first neutralization tank 4, the second soft water tank 5, the second neutralization tank 6, the trap 10, It is constituted by each flow path that communicates with and connects up to the trapping part drainage port 14. Specifically, the trap cleaning channel 51 transfers the raw water flowing in from the inlet 2 to the channel 28, the first soft water tank 3, the channel 29, the first neutralization tank 4, the channel 30, and the second soft water tank. 5. A flow path through which the flow path 31, the second neutralization tank 6, the second supply flow path 36, the on-off valve 23, the capture section 10, and the on-off valve 22 are passed in this order, and discharged from the capture section drain port to the outside of the device. .

<Flow rate measuring section>
The flow rate measurement unit 62 is installed in the flow path 32 that communicates the second neutralization tank 6 and the water intake port 7, and measures the flow rate of water passing through the flow path 32. In addition, in the water softening process, the water that has flowed into the first water softening tank 3 flows through the first neutralization tank 4, the second water softening tank 5, and the second neutralization tank 6 without being distributed. Therefore, it can be considered that the amount of water flowing through the channel before and after water softening is substantially the same. In other words, the flow rate of water measured by the flow rate measurement unit 62 can be considered to be the amount of raw water flowing before water softening and the amount of soft water flowing after water softening.

<Ion concentration measurement unit>
The ion concentration measuring unit 56 is provided on the second supply flow path 36, and measures the ion concentration of the alkaline electrolyzed water that has flowed through the electrolytic cell 9 during the regeneration process and flows into the neutralization cell.

The ion concentration of the alkaline electrolyzed water measured by the ion concentration measuring section 56 is, for example, a pH value (hydrogen ion concentration index). A general-purpose pH meter can be used as the ion concentration measuring section 56. Note that the ion concentration measuring section 56 may measure the ion concentration of the alkaline electrolyzed water in real time during the regeneration process, or may measure the ion concentration at regular intervals (for example, every 5 minutes).

The ion concentration measuring section 56 is provided downstream of the trapping section 10 and upstream of the second neutralization tank 6. By providing the ion concentration measuring section 56 in this manner, the water passed through the ion concentration measuring section 56 becomes alkaline electrolyzed water with precipitates captured by the capturing section 10. Therefore, the possibility that precipitates will directly adhere to the ion concentration measuring section 56 can be reduced, and a decrease in reliability of the ion concentration measuring section 56 can be suppressed. Note that, as described above, the ion concentration measurement section 56 may be provided in the second supply flow path 36, and may be provided, for example, on the downstream side of the electrolytic cell 9 and the upstream side of the trapping section 10. When the ion concentration measuring section 56 is provided downstream of the electrolytic cell 9 and upstream of the trapping section 10, the pH of the alkaline electrolyzed water immediately after flowing out from the electrolytic cell 9 can be measured. In other words, the pH of the alkaline electrolyzed water can be measured while the hydroxide ions in the alkaline electrolyzed water are being used for the precipitation reaction of magnesium hydroxide. Therefore, the pH of the alkaline electrolyzed water produced in the electrolytic cell 9 can be measured with high accuracy.

<Control unit>
Next, each function of the control section 15 according to the present embodiment will be explained with reference to FIG. 9. FIG. 9 is a functional block diagram of the water softening device 1 according to the first embodiment.

The control unit 15 controls execution and stop of each process, such as a water softening process, a regeneration process, a regeneration channel cleaning process, an electrolytic tank cleaning process, and a trapping part cleaning process, and switching between each process.

Specifically, the control unit 15 controls switching between each process, switching from the water softening process to the regeneration process, switching from the regeneration process to the water softening tank regeneration circulation path cleaning process, and water softening tank regeneration circulation path cleaning. Switching from the process to the neutralization tank regeneration circulation flow path cleaning process, switching from the neutralization tank regeneration circulation flow path cleaning process to the regeneration process, switching from the regeneration process to the regeneration flow path cleaning process, switching from the regeneration flow path cleaning process to the electrolysis The switching to the tank cleaning process, the switching from the electrolytic tank cleaning process to the capture part cleaning process, and the switching from the capture part cleaning process to the water softening process are shown.

The control unit 15 also controls the on-off valves 20 and 22 to control the drainage during the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process.

Further, the control unit 15 controls the flow path switching valve 24 to the flow path switching valve 27, the on-off valve 18, the on-off valve 19, the on-off valve 21, and the on-off valve 23, and executes flow path switching.

The control section 15 includes a clock section 55, a storage section 58, and a calculation section 59.

In the neutralization tank regeneration circulation channel cleaning step, the control section 15 uses information on the water flow rate measured by the flow rate measuring section 62 and information on the amount of water flowing through the neutralization tank regeneration channel cleaning channel 48 that is stored in advance in the storage section 58. Based on the water amount information, it is determined whether the water in the neutralization tank regeneration channel cleaning channel 48 has been replaced with raw water. Note that the information on the amount of water in the neutralization tank regeneration channel cleaning channel 48 specifically refers to the amount of water that fills the entire channel of the neutralization tank regeneration channel cleaning channel 48.

The timer 55 measures the time during which the on-off valve 22 is open in the neutralization tank regeneration circulation channel cleaning process. In other words, the timer 55 measures the time required to drain the alkaline electrolyzed water whose pH has increased from the capture unit drain port 14 . The time measured by the clock section 55 is stored in the storage section 58.

The storage unit 58 stores in advance the ratio of the time required for the neutralization tank regeneration circulation cleaning process and the time required for the soft water tank regeneration circulation flow path cleaning process at a predetermined raw water pressure. The storage unit 58 also stores the flow rate of the water softening tank regeneration circulation flow path (soft water tank drainage flow path), the flow rate of the neutralization tank regeneration circulation flow path (neutralization tank drainage flow path), and the flow rate of the water softening tank regeneration circulation flow path (soft water tank drainage flow path). The flow rate ratio of the Japanese tank regeneration circulation channel is memorized. Furthermore, the storage unit 58 stores the opening time of the on-off valve 22 measured by the clock unit 55.

The calculation unit 59 calculates the time required for the neutralization tank regeneration circulation flow path cleaning process measured by the clock unit 55 and stored in the storage unit 58, and the time required for the neutralization tank regeneration circulation flow path cleaning process stored in advance in the storage unit 58. The time required for the water softening tank regeneration circulation flow path cleaning process can be calculated from the ratio of the time required for the water softening tank regeneration circulation flow path cleaning process to the time required for the water softening tank regeneration circulation flow path cleaning process. By calculating the time required for the water softening tank regeneration circulation flow path cleaning step in this manner, it is possible to prevent the water softening tank regeneration circulation flow path cleaning step from being performed for longer than the necessary time. Furthermore, it is possible to suppress the use of raw water in excess of the required amount of water in the water softening tank regeneration circulation channel cleaning process.

Further, based on the pH measurement result of the alkaline electrolyzed water measured by the ion concentration measurement unit 56, the control unit 15 continues the regeneration process if the pH of the measurement result is less than the reference value, and if the pH is higher than the reference value, the control unit 15 continues the regeneration process. In this case, the regeneration process is stopped and control is performed to switch from the regeneration process.

The above is the configuration of the water softening device 1.

Next, the operation of the water softening device 1 will be explained.

<Water softening process, regeneration process, water softening tank regeneration circulation flow path cleaning process, neutralization tank regeneration circulation flow path cleaning process, electrolytic tank cleaning process, and capture section cleaning process>
Next, with reference to FIG. 10, the water softening process, the regeneration process, the water softening tank regeneration circulation flow path cleaning process, the neutralization tank regeneration circulation flow path cleaning process, the electrolytic tank cleaning process, and the trapping part cleaning process of the water softening device 1 are explained. The process will be explained. FIG. 10 is a diagram showing the state of the water softening device 1 during operation.

As shown in FIG. The on-off valve 18 to the on-off valve 23, the flow path switching valve 24 to the flow path switching valve 27, the electrode 41 of the electrolytic cell 9, the first water pump 11, and the second water pump 12 are switched to control the respective flow states. do.

Here, "ON" in FIG. 10 indicates a state where the corresponding on-off valve is "open", a state where the electrode 41 is energized, and a state where the corresponding water pump is operating. Blank columns indicate a state in which the corresponding on-off valve is "closed," a state in which the electrode 41 is not energized, and a state in which the corresponding water pump is stopped.

In addition, "from (component number) to (component number)" in FIG. Indicates the connected state. For example, the flow path switching valve 24 in the water softening process connects each flow path so that water can be sent from the flow path 28 to the flow path 29.

Moreover, "to (component number)" in FIG. 10 indicates a state in which the corresponding flow path switching valve connects the flow path in a direction in which water may be sent to the corresponding component. In this case, although the flow path is connected, the environment is such that it is difficult for water to flow into or out of the softening water tank or neutralization tank where the corresponding flow path switching valve is installed, so the flow path is connected. Water supply from the switching valve is extremely unlikely to occur.

<Water softening process>
First, the operation of the water softening device 1 during the water softening process will be described with reference to the "during water softening" column in FIGS. 2 and 10.

In the water softening device 1, as shown in FIG. 10, in the water softening process, the on-off valve 19 provided in the flow path 28 is opened while the on-off valve 18 is closed. As a result, raw water containing hardness components flows in from the outside. The inflowing raw water flows through the first water softening tank 3, the first neutralization tank 4, the second water softening tank 5, and the second neutralization tank 6 in this order, so the water softening device 1 softens the water from the water intake 7. water (neutral soft water) can be taken out. At this time, the flow path switching valve 24 is in a connected state where water can be sent from the flow path 28 to the flow path 29, the flow path switching valve 25 is in a connected state where water can be sent from the flow path 29 to the flow path 30, and the flow path switching valve 26 is in a connected state where water can be sent from the flow path 29 to the flow path 30. The connected state is such that water can be sent from the channel 30 to the channel 31, and the channel switching valve 27 is in the connected state that water can be transmitted from the channel 31 to the channel 32. The on-off valves 20 to 23 are all in a closed state. Further, the operations of the electrode 41 of the electrolytic cell 9, the first water pump 11, and the second water pump 12 are also stopped.

Specifically, as shown in FIG. 1, in the water softening process, raw water is supplied from the inlet 2 to the first water softening tank 3 through the channel 28 due to the pressure of the raw water flowing in from the outside. The raw water supplied to the first soft water tank 3 flows through a weakly acidic cation exchange resin 33 provided in the first soft water tank 3. At this time, cations that are hardness components in the raw water are adsorbed by the action of the weakly acidic cation exchange resin 33, and hydrogen ions are released (ion exchange is performed). Then, the raw water is softened by removing cations from the raw water. Since the softened water contains many hydrogen ions that have been exchanged with hardness components and flowed out, it is acidified and becomes acidic water (first softened water) with a low pH. Here, water that contains a large amount of permanent hardness components (for example, sulfates such as calcium sulfate or chlorides such as magnesium chloride) should be treated with temporary hardness components (for example, carbonates such as calcium carbonate) when water is softened. pH tends to drop more easily than water containing a large amount of salt. Since water softening is difficult to proceed in a state where the pH is lowered, the water that has passed through the first water softening tank 3 is passed through the first neutralization tank 4 to be neutralized.

The softened water flows through the flow path 29 via the flow path switching valve 24 provided in the first water softening tank 3 and flows into the first neutralization tank 4 . In the first neutralization tank 4, hydrogen ions contained in the softened water are adsorbed by the action of the weakly basic anion exchange resin 34. That is, since hydrogen ions are removed from the water softened by the first water softening tank 3, the decreased pH is increased and neutralized. Therefore, compared to the case where the water softened in the first water softening tank 3 is directly softened in the second water softening tank 5, the water softening process in the second water softening tank 5 progresses more easily.

The water neutralized by the first neutralization tank 4 (neutralized first soft water) flows through the flow path 30 via the flow path switching valve 25 provided in the first neutralization tank 4, and flows through the flow path 30 to the second soft water tank. 5. In the second soft water tank 5, due to the action of the weakly acidic cation exchange resin 33, cations which are hardness components are adsorbed and hydrogen ions are released. The second soft water tank 5 exchanges the hardness components that could not be removed in the first soft water tank 3 with hydrogen ions possessed by the weakly acidic cation exchange resin 33. That is, the water flowing into the second soft water tank 5 is further softened and becomes soft water (second soft water).

The second soft water flows through the flow path 31 via the flow path switching valve 26 provided in the second soft water tank 5 and flows into the second neutralization tank 6 . In the second neutralization tank 6, hydrogen ions contained in the second soft water that has flowed in are adsorbed by the action of the weakly basic anion exchange resin 34. That is, since hydrogen ions are removed from the second soft water, the lowered pH increases, and the water becomes neutral soft water (neutralized second soft water) that can be used as domestic water. The neutralized second soft water flows through the flow path 32 via the flow path switching valve 27 provided in the second neutralization tank 6 and can be taken out from the water intake port 7.

That is, in the water softening process, raw water flows through the first water softening tank 3, the first neutralization tank 4, the second water softening tank 5, and the second neutralization tank 6 in this order. As a result, the raw water containing hard components flows out of the first water softening tank 3 and is neutralized in the first neutralization tank 4 before the pH of the raw water progresses to decrease due to the water softening treatment in the first water softening tank 3. The water is softened in the second water softening tank 5 and neutralized in the second neutralization tank 6. Therefore, compared to the case where a water softening tank and a neutralization tank are each configured as a single unit, it is possible to suppress the decrease in pH of the water flowing through the water softening tank, that is, acidification. Exchange with hydrogen ions held by the weakly acidic cation exchange resin 33 (5) becomes easier. Therefore, it becomes possible to improve water softening performance.

Then, in the water softening device 1, when the time period specified by the control unit 15 arrives or when the water softening process exceeds a certain amount of water, the water softening process is ended and the regeneration process is executed.

<Regeneration process>
Next, the operation of the regeneration device 8 of the water softening device 1 during the regeneration process will be explained in order with reference to the column "During regeneration" in FIGS. 3 and 10.

In the water softening device 1, the first water softening tank 3 and the second water softening tank 5 filled with the weakly acidic cation exchange resin 33 decrease or disappear in their cation exchange ability as they continue to be used. That is, after all the hydrogen ions, which are the functional groups of the cation exchange resin, are exchanged with calcium ions or magnesium ions, which are the hardness components, ion exchange becomes impossible. Even before all of the hydrogen ions are exchanged with hardness components, as the number of hydrogen ions decreases, the ion exchange reaction becomes more difficult to occur, resulting in a decrease in water softening performance. In such a state, hardness components come to be included in the treated water. Therefore, in the water softening device 1, it is necessary to perform regeneration processing of the first water softening tank 3, the second water softening tank 5, the first neutralization tank 4, and the second neutralization tank 6 using the regeneration device 8.

During the regeneration process, the on-off valve 19, the on-off valve 20, and the on-off valve 22 are closed, the on-off valve 18, the on-off valve 21, and the on-off valve 23 are opened, and the flow path switching valve 24 is connected to the neutralization tank bypass flow path 42. The connection state is such that water can be sent to the first recovery channel 37, the flow path switching valve 25 is in a connection state that allows water to be sent from the soft water tank bypass channel 44 to the second recovery channel 38, and the flow path switching valve 26 is in a connection state that allows water to be sent to the first recovery channel 38. The flow path 35 is connected to allow water to be sent to the neutralization tank bypass flow path 42, and the flow path switching valve 27 is connected to the second supply flow path 36 to the soft water tank bypass flow path 44. In other words, the state where the first soft water tank 3 and the second water softener tank 5 are connected, the state where the first neutralization tank 4 and the second neutralization tank 6 are connected, and the state where the drain port 13 and the trapping part drain port 14 are connected are connected. Drainage shall be stopped. As a result, as shown in FIG. 3, a soft water tank regeneration circulation passage 39 and a neutralization tank regeneration circulation passage 40 are formed, respectively.

Then, when the first water pump 11 and the second water pump 12 are operated, the acidic electrolyzed water and the alkaline electrolyzed water in the electrolytic cell 9 flow through the soft water tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40, respectively. circulate.

Further, the electrolytic cell 9 is energized so that the anode has a higher potential than the cathode (positive electrolysis). As a result, during electrolysis, hydrogen ions are generated at the anode, and acidic electrolyzed water is generated near the anode. On the other hand, hydroxide ions are generated at the cathode, and alkaline electrolyzed water is generated near the cathode.

The acidic electrolyzed water generated in the electrolytic cell 9 flows through the first supply flow path 35, is fed into the second soft water tank 5 via the flow path switching valve 26, and flows through the weakly acidic cation exchange resin 33 inside. . Then, the acidic electrolyzed water that has passed through the second soft water tank 5 flows through the neutralization tank bypass flow path 42 and is fed into the first soft water tank 3 via the flow path switching valve 24, where the weakly acidic cations inside The exchange resin 33 is circulated. That is, by passing acidic electrolyzed water through the weakly acidic cation exchange resin 33, the cations (hardness component) adsorbed on the weakly acidic cation exchange resin 33 are combined with hydrogen ions and ions contained in the acidic electrolyzed water. Causes an exchange reaction. As a result, the weakly acidic cation exchange resin 33 is regenerated.

Thereafter, the acidic electrolyzed water that has passed through the first soft water tank 3 contains cations and flows into the first recovery channel 37 . That is, the acidic electrolyzed water containing cations that has passed through the weakly acidic cation exchange resin 33 is recovered into the electrolytic cell 9 via the first recovery channel 37 .

In this way, the soft water tank regeneration circulation flow path 39 is the soft water tank located most downstream from the raw water inlet, and the soft water tank regenerates acidic electrolyzed water into weakly acidic cations, which adsorbs less hardness components than the upstream soft water tank. The weakly acidic cation exchange resin is passed from the downstream side of the second water softening tank 5, which is a water softening tank having the exchange resin 33, and is located upstream and has more hard components adsorbed than the second water softening tank 5. 33 to the downstream side of the first soft water tank 3. In other words, the water softener regeneration circulation flow path 39 circulates the acidic electrolyzed water sent from the electrolytic cell 9 to the second water softener tank 5, and then sends it to the first soft water tank 3 via the neutralization tank bypass flow path 42. This is a flow path through which the first soft water tank 3 flows and flows into the electrolytic cell 9 via the first recovery flow path 37. As a result, during the regeneration process, the acidic electrolyzed water discharged from the electrolytic tank 9 flows into the second softened water tank 5, which has a smaller adsorption amount of hardness components than the first softened water tank 3, and absorbs the hardness components. The acidic electrolyzed water is discharged from the second soft water tank 5 to the first soft water tank 3. In the regeneration of the weakly acidic cation exchange resin 33 in the second soft water tank 5, compared to the first soft water tank 3, hydrogen ions are consumed less in the acidic electrolyzed water. The reduction in concentration can be suppressed. Therefore, it is possible to prevent acidic electrolyzed water containing a large amount of hydrogen ions from flowing into the first soft water tank 3 and re-adsorbing hard components in the first soft water tank 3. Therefore, reduction in regeneration processing efficiency can be suppressed and regeneration time can be shortened.

On the other hand, the alkaline electrolyzed water generated near the cathode of the electrolytic cell 9 flows through the second supply flow path 36 and the trapping section 10, and is fed into the second neutralization tank 6 via the flow path switching valve 27, and is fed into the second neutralization tank 6 through the flow path switching valve 27. It flows through a weakly basic anion exchange resin 34. Then, the alkaline electrolyzed water that has passed through the second neutralization tank 6 flows through the soft water tank bypass flow path 44 and is sent into the first neutralization tank 4 via the flow path switching valve 25 to reduce the weak base inside. It flows through an anion exchange resin 34. That is, by passing alkaline electrolyzed water through the weakly basic anion exchange resin 34, the anions adsorbed on the weakly basic anion exchange resin 34 are combined with hydroxide ions and ions contained in the alkaline electrolyzed water. Causes an exchange reaction. As a result, the weakly basic anion exchange resin 34 is regenerated.

Thereafter, the alkaline electrolyzed water that has passed through the first neutralization tank 4 contains anions and flows into the second recovery channel 38 . That is, the alkaline electrolyzed water containing anions that has passed through the weakly basic anion exchange resin 34 is recovered into the electrolytic cell 9 via the second recovery channel 38 .

In this way, the neutralization tank regeneration circulation flow path 40 is a neutralization tank located most downstream from the inlet of raw water for alkaline electrolyzed water, and has a higher adsorption amount of anions than the neutralization tank on the upstream side. The weakly basic anion exchange resin 34, which is located upstream, has a weakly basic anion exchange resin 34 which has a weakly basic anion exchange resin 34. It was configured to flow into the downstream side of the first neutralization tank 4 having the basic anion exchange resin 34. In other words, the neutralization tank regeneration circulation flow path 40 circulates the alkaline electrolyzed water sent out from the electrolyzer 9 to the second neutralization tank 6, and then flows it to the first neutralization tank 4 via the water softener bypass flow path 44. This is a flow path in which the electrolyte is sent out, circulates through the first neutralization tank 4, and flows into the electrolytic cell 9 via the second recovery flow path 38. As a result, during the regeneration process, alkaline electrolyzed water flows into the second neutralization tank 6, which has a smaller adsorption amount of anions than the first neutralization tank 4, and the alkaline electrolyzed water containing anions flows into the second neutralization tank 6, which has a smaller amount of anions adsorbed than the first neutralization tank 4. It is discharged from the Japanese tank 6 to the first neutralization tank 4. In the regeneration of the weakly basic anion exchange resin 34 in the second neutralization tank 6, the consumption of hydroxide ions in the alkaline electrolyzed water is lower than in the first neutralization tank 4. Compared to regeneration, reduction in hydroxide ion concentration can be suppressed. Therefore, alkaline electrolyzed water containing a large amount of hydroxide ions flows into the first neutralization tank 4, and anions can be prevented from being re-adsorbed in the first neutralization tank 4. Therefore, reduction in regeneration processing efficiency can be suppressed and regeneration time can be shortened.

In the first embodiment, hardness components, which are cations released from the first water softening tank 3 and the second water softening tank 5 according to the progress of the regeneration process, react with alkaline electrolyzed water in the electrolytic tank 9. As a result, precipitates are formed.

Examples of precipitates include calcium carbonate and magnesium hydroxide. It has been confirmed that calcium carbonate precipitates as a powdery solid, and magnesium hydroxide precipitates as a gel-like hydrated solid. Precipitates derived from these hardness components are captured as precipitates in the capture section 10 provided in the second supply channel 36. However, since magnesium hydroxide precipitates as a hydrated solid, its specific gravity is much lighter than that of calcium carbonate. That is, magnesium hydroxide has a much larger volume compared to calcium carbonate based on the same weight, and when it is generated as a precipitate, it quickly blocks the trapping section 10. If the trapping section 10 is completely blocked, alkaline electrolyzed water cannot pass through the trapping section 10 and will not circulate through the neutralization tank regeneration circulation channel 40, and the regeneration of the weakly basic anion exchange resin 34 will not proceed. Furthermore, even if the trapping section 10 is not completely clogged, the amount of alkaline electrolyzed water passing through the trapping section 10 is significantly reduced, resulting in a delay in the regeneration of the weakly basic anion exchange resin 34. . Therefore, when magnesium hydroxide is generated as a precipitate (specific precipitate) in the alkaline electrolyzed water, it is necessary to immediately stop the power supply to the electrolytic cell 9.

Here, an example of the solubility product of calcium carbonate and magnesium hydroxide in alkaline electrolyzed water in the first embodiment is shown in FIG. FIG. 11 is a diagram showing the product of the pH of alkaline electrolyzed water and the solubility of precipitates. When the pH is around 7 to 12, calcium carbonate precipitates in a constant amount regardless of the pH. On the other hand, magnesium hydroxide begins to be generated when the pH exceeds 9.6, rapidly precipitates, and when the pH exceeds 10.0, the amount of precipitation becomes almost constant, indicating that it occurs frequently. Therefore, in order to suppress large amounts of magnesium hydroxide from being deposited in the alkaline electrolyzed water, the pH of the alkaline electrolyzed water is measured, and the regeneration process of the water softening device 1 is stopped before the pH exceeds 10 for a long time. Control as follows.

Below, the factors that cause the pH of alkaline electrolyzed water to increase will be explained.

In the regeneration step in the first embodiment, hydroxide ions are generated on the cathode side by electrolysis of water in the electrolytic cell 9. That is, hydroxide ions are continuously supplied from the electrolytic cell 9 into the alkaline electrolyzed water in the neutralization tank regeneration circulation channel 40 . The supplied hydroxide ions cause an ion exchange reaction with anions adsorbed on the weakly basic anion exchange resin 34, and the weakly basic anion exchange resin 34 is regenerated. As the regeneration process progresses, the total amount of anions adsorbed on the weakly basic anion exchange resin 34 decreases. Therefore, the amount of exchange per unit time in the ion exchange reaction of hydroxide ions and anions gradually decreases. That is, the amount of hydroxide ions per unit time supplied from the electrolytic cell 9 into the alkaline electrolyzed water in the neutralization tank regeneration circulation channel 40 is the anion adsorbed on the weakly basic anion exchange resin 34. The total amount of hydroxide ions in the neutralization tank regeneration circulation channel 40 increases because the amount of hydroxide ions per unit time causes an ion exchange reaction. Therefore, as the regeneration process progresses, the pH of the alkaline electrolyzed water in the neutralization tank regeneration circulation flow path 40 increases.

In this way, the pH of the alkaline electrolyzed water in the neutralization tank regeneration circulation flow path 40, which was neutral immediately after the start of the regeneration process, gradually increases as the regeneration process progresses, and then naturally decreases. Never. Therefore, if the pH exceeds pH 9.6, which is the standard value at which magnesium hydroxide is generated, or pH 10.0, which is the standard value at which magnesium hydroxide occurs frequently, the regeneration process is immediately stopped and the pH Drain the alkaline electrolyzed water that has risen. Specifically, at the stage where the regeneration process is stopped, the process moves to the soft water tank regeneration circulation channel cleaning process.

Note that whether to use a pH value at which magnesium hydroxide occurs or a pH value at which magnesium hydroxide frequently appears can be selected depending on the size of the trapping section 10 and the like as the reference value.

Note that if the user wants to obtain soft water during the regeneration process, by opening a faucet (not shown) etc. connected to the water softening device 1, the raw water passes through the bypass flow path 53 from the inlet 2. Since it flows out from the water intake port 7, the raw water can be used without waiting for the completion of the regeneration process.

<Soft water tank regeneration circulation channel cleaning process>
Next, the operations of the water softening device 1 during the water softening tank regeneration circulation flow path cleaning process will be described in order with reference to the column "When cleaning the water softener tank regeneration flow path" in FIGS. 4 and 10.

In the water softening device 1, during the regeneration process, hardness components are released into the acidic electrolyzed water from the first water softening tank 3 and the second water softening tank 5, and the acidic electrolyzed water is discharged from the water softening tank regeneration circulation flow path 39. It circulates in the flow path without any problem. Therefore, the soft water tank regeneration circulation channel 39 during the regeneration process is filled with high hardness water containing hardness components released from the first soft water tank 3 and the second soft water tank 5. As mentioned above, when the hardness components contained in this highly hard water move toward the alkaline electrolyzed water side in the electrolytic cell 9, precipitates are generated by reaction, and especially when a large amount of magnesium hydroxide is precipitated, the trapping part 10 is immediately removed. It causes blockage. As a method of reducing the amount of these precipitates generated, there is a method of draining the highly hard water in the water softening tank regeneration circulation channel 39. Therefore, in order to solve these problems, the regeneration operation is stopped when the pH of the alkaline electrolyzed water exceeds a predetermined condition, for example, pH 10, during the regeneration process, and the high temperature inside the water softener tank regeneration circulation flow path 39 is stopped. A cleaning process is carried out for the soft water tank regeneration circulation channel that drains hard water. Note that the predetermined conditions refer to a case where the pH exceeds a pH at which precipitation of magnesium hydroxide frequently occurs.

During the water softening tank regeneration circulation channel cleaning step, the on-off valves 21 to 23 are closed, the on-off valves 18 to 20 are opened, and the channel switching valve 24 switches the channel 28 from the neutralization tank bypass channel. 42, the flow path switching valve 25 is connected to allow water to be sent to the soft water tank bypass flow path 44, and the flow path switching valve 26 is connected from the neutralization tank bypass flow path 42 to the first supply flow path 35. The connection state is such that water can be fed, and the flow path switching valve 27 is in a connection state that allows water to be fed to the second supply flow path 36. That is, a state in which the first soft water tank 3 and the second water softener tank 5 are in communication connection, a state in which the second water softener tank 5 and the drain port 13 are in communication connection, a state in which the electrolytic cell 9 and the drain port 13 are in communication connection, Then, the drainage from the trapping part drain port 14 is stopped. Thereby, as shown in FIG. 4, a first drainage channel 46 and a second drainage channel 47 are respectively formed. In other words, a soft water tank acidic channel cleaning channel is formed. Note that at this time, the operations of the electrode 41, the first water pump 11, and the second water pump 12 are stopped.

In the soft water tank regeneration circulation flow path cleaning process, specifically, raw water from the outside flows into the first drainage flow path 46 and the second drainage flow path 47 by opening the on-off valve 19.

In the first drainage flow path 46, the high hardness water in the flow path 28, the first recovery flow path 37, the first water pump 11, the electrolytic cell 9, and the first supply flow path 35 is washed away by the pressure of the inflowing raw water. , flows into the drainage channel 54. The high hardness water that has flowed into the drainage channel 54 is discharged from the drainage port 13 to the outside of the apparatus.

In the second drainage flow path 47, the high hardness water in the flow path 28, the first soft water tank 3, the neutralization tank bypass flow path 42, the second water softener tank 5, and the first supply flow path 35 is is swept away and flows into the drainage channel 54. The high hardness water that has flowed into the drainage channel 54 is discharged from the drainage port 13 to the outside of the apparatus.

In this way, by the water softening tank regeneration circulation flow path cleaning step, the high hardness water in the first drainage flow path 46 and the second drainage flow path 47, which are the main locations where high hardness water remains when the regeneration step is stopped, is removed. It can be replaced with raw water.

Moreover, because of this, the high hardness water is drained out of the apparatus through a flow path that does not include a neutralization tank, so that the high hardness water can be drained out of the apparatus without flowing into the neutralization tank. In other words, since the hydrogen ions in the acidic water stored in the soft water tank regeneration circulation flow path 39 can be drained while being prevented from being adsorbed to the weakly basic anion exchange resin 34 in the neutralization tank, when the regeneration process is restarted, This can reduce the possibility that the time required to regenerate the neutralization tank will become longer.

In the water softening device 1, when the time period specified by the control unit 15 has arrived, or when the water softening tank regeneration circulation channel cleaning process exceeds a certain period of time (for example, 1 minute), or when the water softening tank regeneration circulation flow When the amount of water flowing in the path cleaning step exceeds a certain value, the soft water tank regeneration circulation flow path cleaning step is ended, and the neutralization tank regeneration circulation flow path cleaning step is executed.

In addition, if the user wants to obtain soft water during the water softening tank regeneration circulation channel cleaning process, by opening a faucet (not shown) etc. connected to the water softening device 1, the raw water is bypassed from the inlet 2. Since it passes through the flow path 53 and flows out from the water intake port 7, the raw water can be used without waiting for the end of the soft water tank regeneration circulation flow path cleaning process.

<Neutralization tank regeneration circulation channel cleaning process>
Next, the operations of the water softening device 1 during the cleaning process of the neutralization tank regeneration circulation channel will be described in order with reference to the column ``When cleaning the neutralization tank regeneration flow path'' in FIGS. 5 and 10.

In the water softening device 1, during the regeneration process, alkaline electrolyzed water generated near the cathode of the electrolytic cell 9 is sent to the first neutralization tank 4 and the second neutralization tank 6, and the hydroxyl contained in the alkaline electrolyzed water is removed. A part of the substance ions undergoes an ion exchange reaction with the anions adsorbed on the weakly basic anion exchange resin, and the anions are released, and the alkaline electrolyzed water is discharged from the neutralization tank regeneration circulation flow path 40. It circulates in the flow path without any problem. Therefore, as the regeneration process progresses, the water filling the neutralization tank regeneration circulation flow path 40 becomes water with increased concentrations of hydroxide ions and anions. That is, it means that the pH gradually increases. As mentioned above, in the electrolytic cell 9, when the hardness components contained in the high hardness water filled in the soft water tank regeneration circulation channel 39 move to the alkaline electrolyzed water, precipitates are reacted and generated, especially If a large amount of magnesium hydroxide is generated, the trapping section 10 will be quickly clogged. As a method of reducing the amount of these precipitates generated, there is a method of draining the alkaline electrolyzed water whose pH has increased in the neutralization tank regeneration circulation channel 40. Therefore, in order to solve the problem of clogging of the capture unit 10 due to precipitates, the regeneration operation is stopped when the pH of the alkaline electrolyzed water reaches a predetermined condition (for example, when the pH exceeds 10) during the regeneration process. Then, a neutralization tank regeneration circulation channel cleaning step is performed to drain the alkaline electrolyzed water whose pH has increased in the neutralization tank regeneration circulation channel 40.

During the neutralization tank regeneration circulation flow path cleaning process, on-off valves 19 to 20 and on-off valves 23 are closed, on-off valves 18 and on-off valves 21 to 22 are opened, and flow path switching valves 24 is in a connected state that allows water to be sent to the neutralization tank bypass channel 42, the flow path switching valve 25 is in a connected state that allows water to be sent from the soft water tank bypass channel 44 to the second recovery channel 38, and the flow path switching valve 26 is in a connected state that allows water to be sent to the second recovery channel 38. The connection state is such that water can be sent to one supply channel 35, and the flow path switching valve 27 is in a connected state that water can be sent from the flow path 32 to the soft water tank bypass flow path 44. That is, the first neutralization tank 4 and the second neutralization tank 6 are in a communicating state, and the first neutralizing tank 4 and the trapping part drain port 14 are in a communicating state. Thereby, as shown in FIG. 5, a fifth drainage path 63 (neutralization tank regeneration channel cleaning channel) is formed. Note that at this time, the operations of the electrode 41, the first water pump 11, and the second water pump 12 are stopped.

In the neutralization tank regeneration path cleaning process, specifically, by opening the on-off valve 22, raw water flows from the outside into the fifth drainage flow path 63, and the flow rate of the raw water flowing into the flow path 32 is measured. 62.

In the fifth drainage flow path 63, the pressure of the incoming raw water pushes the alkaline electrolyzed water with an increased pH from the flow path 32, the second recovery flow path 38, the second water supply pump 12, the electrolytic cell 9, part of the second supply flow path 36, and the capture unit 10, and the alkaline electrolyzed water is discharged outside the device from the capture unit drain 14 located at the bottom of the capture unit 10.

In this way, the alkaline electrolyzed water whose pH has increased in the fifth drainage flow path 63, which is the residual location of the alkaline electrolyzed water whose main pH has increased when the regeneration process is stopped, is caused by the neutralization tank regeneration circulation flow path cleaning process. can be replaced with raw water.

After the highly hard acidic electrolyzed water and high pH alkaline electrolyzed water generated in the regeneration process are discharged from the equipment through the soft water tank regeneration circulation flow path cleaning process and the neutralization tank regeneration circulation flow path cleaning process, the process is stopped. The regeneration step is restarted, and the regeneration step is carried out until the regeneration of the weakly acidic cation exchange resin 33 and the weakly basic anion exchange resin 34 is completed. Note that the stopping of the regeneration process, the soft water tank regeneration circulation flow path cleaning step, and the neutralization tank regeneration circulation flow path cleaning step are performed until the regeneration of the weakly acidic cation exchange resin 33 and the weakly basic anion exchange resin 34 is completed. It may be provided multiple times.

<Regeneration channel cleaning process>
Next, the operation of the water softening device 1 during the regeneration channel cleaning step will be described in order with reference to the column "During regeneration channel cleaning" in FIGS. 4 and 10.

In the water softening device 1, during the regeneration process, hardness components are released into the acidic electrolyzed water from the first water softening tank 3 and the second water softening tank 5, and the acidic electrolyzed water is discharged from the water softening tank regeneration circulation flow path 39. It circulates in the flow path without any problem. Therefore, after the completion of the regeneration process, the soft water tank regeneration circulation channel 39 is filled with highly hard water containing the hardness components released from the first soft water tank 3 and the second soft water tank 5. The hardness of this high-hardness water is significantly higher than the hardness of raw water (for example, 450 ppm), and may rise to, for example, about 2000 ppm. When the water softening process is started with this high hardness water remaining in the water softening device 1, high hardness water or mixed water of raw water and high hardness water is discharged from the water intake port 7. Therefore, if the user of the water softening device 1 executes the water softening process after the regeneration process is finished, he will not be able to obtain soft water immediately after the start of the water softening process, but will instead obtain water that is harder than the raw water. there is a possibility.

Further, highly hard water flows through the weakly acidic cation exchange resin 33 in the first soft water tank 3 and the second soft water tank 5. In other words, even though the weakly acidic cation exchange resin 33 is regenerated by replacing the hardness components adsorbed during the water softening process with hydrogen ions during the regeneration process, it contains hardness components again. Water will be distributed. Therefore, due to the regeneration process that has been carried out, an exchange reaction occurs between the hydrogen ions filled in the weakly acidic cation exchange resin 33 and the hard components in the high hardness water, and the hard components are adsorbed to the weakly acidic cation exchange resin 33 again. Therefore, hydrogen ions available for softening raw water decrease, resulting in a decrease in water softening performance.

To solve these problems, a regeneration flow path cleaning process is carried out to drain the high-hardness water from the soft water tank regeneration circulation flow path 39.

During the regeneration channel cleaning step, the on-off valves 21 to 23 are closed, the on-off valves 18 to 20 are opened, and the channel switching valve 24 sends water from the channel 28 to the neutralization tank bypass channel 42. The flow path switching valve 25 is in a connected state in which water can be sent to the soft water tank bypass flow path 44, and the flow path switching valve 26 is in a connected state in which water can be sent from the neutralization tank bypass flow path 42 to the first supply flow path 35. The connection state is established, and the flow path switching valve 27 is brought into a connection state in which water can be supplied to the second supply flow path 36. That is, a state in which the first soft water tank 3 and the second water softener tank 5 are in communication connection, a state in which the second water softener tank 5 and the drain port 13 are in communication connection, a state in which the electrolytic cell 9 and the drain port 13 are in communication connection, Then, the drainage from the trapping part drain port 14 is stopped. Thereby, as shown in FIG. 4, a first drainage channel 46 and a second drainage channel 47 are respectively formed. Note that at this time, the operations of the electrode 41, the first water pump 11, and the second water pump 12 are stopped.

In the regeneration channel cleaning step, specifically, by opening the on-off valve 19, raw water flows into the first drainage channel 46 and the second drainage channel 47 from the outside.

In the first drainage flow path 46, the high hardness water in the flow path 28, the first recovery flow path 37, the first water pump 11, the electrolytic cell 9, and the first supply flow path 35 is washed away by the pressure of the inflowing raw water. , flows into the drainage channel 54. The high hardness water that has flowed into the drainage channel 54 is discharged from the drainage port 13 to the outside of the apparatus.

In the second drainage flow path 47, the high hardness water in the flow path 28, the first soft water tank 3, the neutralization tank bypass flow path 42, the second water softener tank 5, and the first supply flow path 35 is is swept away and flows into the drainage channel 54. The high hardness water that has flowed into the drainage channel 54 is discharged from the drainage port 13 to the outside of the apparatus.

In this way, through the regeneration flow path cleaning step, the high hardness water in the first drainage flow path 46 and the second drainage flow path 47, which are the main areas where high hardness water remains after the regeneration step, is transferred to the neutralization tank. It is possible to replace it with raw water while suppressing the distribution of water. Therefore, in the regeneration flow path cleaning process, it is possible to suppress the adsorption of hydrogen ions to the weakly basic anion exchange resin 34 in the neutralization tank, so it is possible to suppress the consumption of the filled hydroxide ions and improve the neutralization performance. can be kept. Therefore, deterioration in water softening performance caused by highly hard water can be suppressed.

Note that the control unit 15 supplies raw water to each flow path so that the flow rate of raw water flowing through the second drainage flow path 47 is larger than the flow rate of raw water flowing through the first drainage flow path 46.

As a result, high hardness water in the second drainage flow path 47, which is a flow path that includes a water softening tank used during the water softening process and in which drainage of high hardness water in the flow path is essential, is prioritized. It can be replaced with raw water. Therefore, it is possible to suppress a decrease in water softening performance caused by highly hard water when the water softening process is started. In addition, it is possible to reduce the amount of water discharged from the first drainage flow path 46, which is not used during the water softening process and has little effect on the water softening process even if high hardness water remains, thereby reducing waste. Drainage can be prevented and the amount of water required for the regeneration channel cleaning process can be suppressed.

Moreover, as a result, highly hard water is drained out of the apparatus through a flow path that does not include a neutralization tank. In other words, since the hard components in the high hardness water stored in the water softening tank regeneration circulation flow path 39 can be drained while suppressing adsorption to the weakly basic anion exchange resin 34 in the neutralization tank, during the regeneration process. It is possible to prevent the decline in water softening performance caused by high hardness water that occurs in the water and maintain the water softening performance.

In the water softening device 1, when the time period specified by the control unit 15 has arrived, or when the regeneration channel cleaning process exceeds a certain period of time (for example, 1 minute), or when the regeneration channel cleaning process When the amount of water exceeds a certain value, the regeneration channel cleaning step is ended and the electrolytic tank cleaning step is executed.

Note that if the user wants to obtain soft water during the regeneration channel cleaning process, by opening a faucet (not shown) etc. connected to the water softening device 1, the raw water flows from the inlet 2 to the bypass channel 53. Since the raw water flows out through the water intake port 7, the raw water can be used without waiting for the completion of the regeneration channel cleaning process.

<Electrolytic tank cleaning process>
Next, the operation of the water softening device 1 during the electrolytic cell cleaning process will be described in order with reference to the column "During electrolytic cell cleaning" in FIGS. 7 and 10.

In the regeneration process, when the electrolytic cell 9 is operating, hardness components (calcium ions or magnesium ions) in the water are deposited as a solid (scale) on the cathode. Since the precipitate deposited on the cathode is a nonconductor, it increases the operating voltage of the electrolytic cell 9 and increases the power consumption during the regeneration process. Therefore, it is necessary to perform an electrolytic cell cleaning step to remove the precipitates deposited on the cathode.

In the electrolytic cell cleaning step, the on-off valves 18 to 22 are opened, and the on-off valve 23 is closed. In addition, the flow path switching valve 24 is in a connected state where water can be sent from the flow path 28 to the flow path 29, the flow path switching valve 25 is in a connected state where water can be sent to the soft water tank bypass flow path 44, and the flow path switching valve 26 is in a connected state where water can be sent to the water softening tank bypass flow path 44. The connection state is such that water can be sent to the first supply flow path 35, and the flow path switching valve 27 is connected to the second supply flow path 36, so that water can be sent to the second supply flow path 36. That is, the first soft water tank 3 and the electrolytic cell 9 are in a communicating state, the electrolytic cell 9 and the drain port 13 are in a communicating state, and the electrolytic cell 9 and the trapping part drain port 14 are in a communicating state. Thereby, as shown in FIG. 7, a first drainage channel 46 and a third drainage channel 50 are respectively formed.

In the electrolytic cell cleaning step, specifically, by opening the on-off valve 19, raw water flows into the first drainage channel 46 and the third drainage channel 50 from the outside.

In the first drainage flow path 46, the raw water that has flowed in flows through the flow path 28, the first recovery flow path 37, and the first water pump 11, and then flows into the electrolytic cell 9.

On the other hand, in the third drainage flow path 50, the raw water that has flowed in flows through the flow path 28, the first water softening tank 3, the second recovery flow path 38, and the second water pump 12, and then flows into the electrolytic cell 9.

In the electrolytic cell cleaning step, the control unit 15 applies electricity so that the cathode has a higher potential than the anode (reverse electrolysis). Therefore, the electrolytic cell 9 electrolyzes the raw water that has flowed into the electrolytic cell, producing alkaline electrolyzed water near the anode and producing acidic electrolyzed water near the cathode.

At this time, the precipitates deposited on the cathode can be dissolved by the acidic electrolyzed water generated at the cathode. Therefore, deterioration of electrolytic performance due to attachment of precipitates to the surface of the electrode 41 can be suppressed.

The alkaline electrolyzed water generated at the anode flows through the first supply channel 35, flows into the drainage channel 54, and is discharged from the drain port 13 to the outside of the apparatus.

On the other hand, the acidic electrolyzed water generated at the cathode dissolves the precipitates deposited on the cathode, flows through the second supply channel 36, and flows into the trapping section 10. The acidic electrolyzed water that has flowed into the trapping section 10 can dissolve precipitates stuck to the trapping section 10, and can preliminarily clean the trapping section 10. Therefore, the time required for the next step, the capturing section cleaning step, can be shortened. The acidic electrolyzed water is then discharged to the outside of the apparatus from a trapping section drain port 14 provided at the lower part of the trapping section 10.

That is, in the electrolytic cell cleaning process, the removal of precipitates in the electrolytic cell 9 and the precipitates in the trapping part 10 can be performed simultaneously, reducing the time required from the end of the regeneration process to the start of the water softening process. Can be done.

Then, in the water softening device 1, when the time period specified by the control unit 15 has arrived or when the electrolytic cell cleaning process exceeds a certain period of time (for example, 5 minutes), the electrolytic cell cleaning process is finished, and the trapping part is cleaned. Execute the process.

In addition, in the third drainage channel 50, since the raw water passes through the first soft water tank 3, the acidified water passes through the trapping part 10. Therefore, the trapping section 10 becomes acidic, and the precipitates fixed to the trapping section 10 are dissolved by the acidic water. Therefore, since the trapping section 10 can be preliminarily cleaned, the time required for the next step, the trapping section cleaning step, can be shortened. That is, the removal of the precipitates in the electrolytic bath 9 and the precipitates in the trapping part 10 can be performed simultaneously, and the time required from the end of the regeneration process to the start of the water softening process can be shortened.

In addition, if the user wants to obtain soft water during the electrolyzer cleaning process, by opening a faucet (not shown) etc. connected to the water softening device 1, the raw water flows from the inlet 2 to the bypass channel 53. Since the raw water flows out from the water intake port 7, the raw water can be used without waiting for the completion of the electrolytic cell cleaning process.

<Catching part cleaning process>
Next, the operation of the water softening device 1 during the trapping section cleaning process will be described in order with reference to the column "When cleaning the trapping section" in FIGS. 8 and 10.

In the regeneration process, highly hard water containing hard components released from the first soft water tank 3 and the second soft water tank 5 flows into the electrolytic cell 9. The hardness component moves to the cathode side during electrolysis, reacts with hydroxide ions generated at the cathode, and becomes a precipitate. A part of the deposited precipitate is contained in the alkaline electrolyzed water discharged from the electrolytic cell 9, flows through the second supply channel 36, and is captured by the capture unit 10. Therefore, since precipitates gradually accumulate in the trapping section 10 during the regeneration process, the pressure loss caused by the trapping section 10 gradually increases, and the alkaline electrolyzed water flowing through the neutralization tank regeneration circulation channel 40 The flow rate gradually decreases. Therefore, if the precipitate is left as it is, the time required to regenerate the weakly basic anion exchange resin 34 in the first neutralization tank 4 and the second neutralization tank 6 will be extended, and eventually the weakly basic anion exchange resin 34 There is a risk that the filling of hydroxide ions into the tank may not be completed. Therefore, it is necessary to perform a trap cleaning step to remove precipitates that have adhered to or deposited on the trap 10.

In the trap cleaning step, the on-off valve 18, the on-off valve 19, the on-off valve 22, and the on-off valve 23 are opened, and the on-off valve 20 and the on-off valve 21 are closed. In addition, the flow path switching valve 24 is in a connected state that allows water to be sent from the flow path 28 to the flow path 29, the flow path switching valve 25 is in a connected state that allows water to be sent from the flow path 29 to the flow path 30, and the flow path switching valve 26 is in a connected state that allows water to be sent from the flow path 29 to the flow path 30. The connection state is such that water can be sent from the flow path 30 to the flow path 31, and the flow path switching valve 27 is connected to be able to send water from the flow path 31 to the second supply flow path 36. That is, a state in which the first soft water tank 3 and the first neutralization tank 4 are connected in communication, a state in which the first neutralization tank 4 and the second soft water tank 5 are connected in communication, and a state in which the second soft water tank 5 and the second neutralization tank are connected in communication. A state in which the tank 6 is in communication with the second neutralization tank 6 and a state in which the second neutralization tank 6 and the trapping part drain port 14 are in communication connection with each other. Thereby, as shown in FIG. 8, a fourth drainage channel 52 is formed.

In the capture section cleaning step, specifically, by opening the on-off valve 19, raw water flows into the channel 28 from the outside. The raw water that has flowed into the flow path 28, the first soft water tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second soft water tank 5, the flow path 31, the second neutralization tank 6, and the second supply. It flows through the flow path 36 and flows into the trapping section 10 .

In the trapping section 10, neutral soft water flows from the opposite side to the water flow direction in the regeneration process. In other words, the neutral soft water that flows in performs backwashing of the trapping section 10. At this time, since some of the precipitates that have adhered or precipitated on the trapping section 10 in the electrolytic tank cleaning process have been dissolved in advance, the trapping section 10 can be easily cleaned with neutral soft water. Neutral soft water containing precipitates is discharged to the outside of the apparatus from a trapping section drain port 14 provided at the bottom of the trapping section 10.

In this way, since the trapping section 10 can be backwashed, precipitates remaining in the trapping section 10 can be removed. Therefore, clogging of the trapping section 10 can be suppressed, and pressure loss caused by the trapping section 10 can be reduced when performing the regeneration process again. As a result, it is possible to suppress a reduction in the flow rate of the neutralization tank regeneration circulation flow path 40, which is a regeneration flow path including the capture section 10, and to ensure the flow rate of alkaline electrolyzed water, thereby ensuring regeneration performance.

Then, in the water softening device 1, when the time period specified by the control unit 15 arrives or when the trapping portion cleaning step exceeds a certain period of time (for example, 5 minutes), the trapping portion cleaning step is ended, and the water softening step is completed. Execute.

Note that the flow path from the inlet 2 to the second neutralization tank 6 is the same flow path as the flow path during the water softening process. That is, by using the fourth drainage flow path 52, the second neutralization tank 6, which is the final neutralization tank in the water softening process, is filled with softened water. Therefore, by performing the water softening process after performing the trap cleaning process using the fourth drainage flow path 52, the user of the water softening device 1 can receive water softening treatment to reduce hardness immediately after starting the water softening process. Soft water can be obtained from the water intake port 7.

In addition, if the user wants to obtain soft water during the trap cleaning process, by opening a faucet (not shown) etc. connected to the water softening device 1, the raw water flows from the inlet 2 to the bypass channel 53. Since the raw water flows out from the water intake port 7, the raw water can be used without waiting for the completion of the trap cleaning process.

As described above, in the water softening device 1, the water softening process, the regeneration process, the water softening tank regeneration path cleaning process, the neutralization tank regeneration circulation flow path cleaning process, the regeneration process, the regeneration flow path cleaning process, the electrolytic tank cleaning process, The trapping section cleaning step is repeatedly executed in this order. By performing the trap cleaning step immediately before the water softening step, the last stage neutralization tank in the water softening step is filled with softened water. Therefore, when the user of the water softening device 1 opens the faucet, discharge of highly hard water from the water intake port 7 can be suppressed, and soft water with stable hardness can be provided immediately after the start of the water softening process.

In addition, by performing the electrolytic tank cleaning process after performing the regeneration channel cleaning process, the high hardness water has already been drained out of the equipment at the time of polarity reversal in the electrolytic tank cleaning process, making it possible to electrolyze the high hardness water. You can suppress your sexuality. Therefore, electrolysis of highly hard water can be suppressed, and generation of a large amount of scale in the channel through which alkaline electrolyzed water is fed during polarization can be suppressed.

As mentioned above, according to the water softening device 1 according to the first embodiment, the following effects can be enjoyed.

(1) The water softening device 1 includes a water softening tank that generates acidic soft water by softening raw water containing hard components using a weakly acidic cation exchange resin 33, and a weakly basic anion to adjust the pH of the acidic soft water that has passed through the water softening tank. Control for controlling a neutralization tank that generates neutralized soft water by neutralizing with the exchange resin 34, and a regeneration process that is a process of regenerating the weakly acidic cation exchange resin 33 and/or the weakly basic anion exchange resin 34. 15, an electrolytic cell 9 that generates acidic electrolyzed water used for regenerating the weakly acidic cation exchange resin 33 and alkaline electrolyzed water used for regenerating the weakly basic anion exchange resin 34, and an alkaline electrolyzed water. The ion concentration measurement unit 56 is provided to measure the ion concentration of the ion concentration. The control unit 15 controls execution of the regeneration process based on the ion concentration measurement result measured by the ion concentration measurement unit 56 during the regeneration process, and continues the regeneration process if the ion concentration measurement result is less than the reference value. If the ion concentration measurement result is equal to or higher than the reference value, the regeneration process is stopped.

According to such a configuration, the regeneration process can be stopped based on the ion concentration of the alkaline electrolyzed water. Therefore, the regeneration step can be carried out using alkaline electrolyzed water with an ion concentration lower than that at which specific precipitates are rapidly deposited in the alkaline electrolyzed water, and the regeneration step can be carried out smoothly.

(2) In the water softening device 1, the reference value is an ion concentration at which a specific precipitate is generated due to the reaction between ions in the alkaline electrolyzed water and the hardness component, and is, for example, a pH of 10.0.

According to such a configuration, the control unit 15 can stop the regeneration process when the pH, which is a pH condition under which a specific precipitate rapidly precipitates, becomes 10.0 or higher.

(3) In the water softening device 1, the on-off valve 18 to the on-off valve 23, the flow path switching valve 24 to the flow path switching valve 27, and the high hardness filled in the water softening tank regeneration circulation flow path 39 during the regeneration process a cleaning channel 45 for replacing the acidic electrolyzed water with raw water; and a neutralization channel for replacing the alkaline electrolyzed water with a high pH value filled in the neutralization tank regeneration circulation channel 40 with raw water during the regeneration process. A tank regeneration channel and a cleaning channel 48 are provided. According to such a configuration, after the pH of the alkaline electrolyzed water becomes equal to or higher than the reference value and the regeneration process is stopped, the control unit 15 controls the on-off valves 18 to 23 and the flow path switching valve 24 to the flow path switching valve. By switching 27 to configure the water softening tank regeneration channel cleaning channel 45 and the neutralization tank regeneration channel cleaning channel, the acidic electrolyzed water in the water softening tank regeneration circulation channel 39 can be replaced with raw water. , the alkaline electrolyzed water in the neutralization tank regeneration circulation channel 40 can be replaced with raw water. Therefore, it is possible to restart the regeneration process while suppressing rapid precipitation of specific precipitates into the alkaline electrolyzed water.

The present invention has been described above based on the embodiments. Those skilled in the art will understand that these embodiments are merely illustrative, and that various modifications can be made to the combinations of their constituent elements or processing processes, and that such modifications are also within the scope of the present invention. This is where I am.

In the water softening device 1 according to the first embodiment, after the regeneration process is completed, the regeneration channel cleaning process, the electrolytic tank cleaning process, and the trapping part cleaning process are performed in this order, but the present invention is not limited to this. For example, the regeneration channel cleaning step may be performed after the electrolytic cell cleaning step, and the trapping portion cleaning step may be performed before the water softening step. Even if the inside of the apparatus is cleaned in this order, the precipitates in the electrolytic cell 9 and the trapping section can be removed, and the second neutralization tank 6 immediately before the water softening process can be filled with soft water.

The water softening device according to the present invention can be applied to a point of use (POU) or a point of entry (POE) water purification device.

1 Water softening device 2 Inlet 3 First water softening tank 4 First neutralization tank 5 Second water softening tank 6 Second neutralization tank 7 Water intake 8 Regeneration device 9 Electrolytic cell 10 Capture unit 11 First water pump 12 Second water supply Pump 13 Drain port 14 Capture part drain port 15 Control part 18, 19, 20, 21, 22, 23 On-off valve 24, 25, 26, 27 Flow path switching valve 28, 29, 30, 31, 32 Flow path 33 Weak acidic Cation exchange resin 34 Weakly basic anion exchange resin 35 First supply flow path 36 Second supply flow path 37 First recovery flow path 38 Second recovery flow path 39 Soft water tank regeneration circulation flow path 40 Neutralization tank regeneration circulation flow Channel 41 Electrode 41a Electrode 41b Electrode 42 Neutralization tank bypass flow path 43 Water softening flow path 44 Water softening tank bypass flow path 45 Water softening tank regeneration flow path Washing flow path 46 First drainage flow path 47 Second drainage flow path 48 Neutralization tank Regeneration channel cleaning channel 49 Electrolytic cell cleaning channel 50 Third drainage channel 51 Capture section cleaning channel 52 Fourth drainage channel 53 Bypass channel 54 Drain channel 55 Timing section 56 Ion concentration measurement section 58 Storage section 62 Flow rate measuring section 63 Fifth drainage channel 64 Regeneration channel cleaning channel

Claims (9)

A water softening tank that softens raw water containing hard components using a weakly acidic cation exchange resin;
a neutralization tank that neutralizes the soft water that has passed through the soft water tank with a weakly basic anion exchange resin;
An electrolytic cell that generates alkaline electrolyzed water,
an ion concentration measurement unit that measures the ion concentration of the alkaline electrolyzed water produced in the electrolytic cell;
a control unit that controls a regeneration step that is a step of regenerating the weakly basic anion exchange resin;
Equipped with
The control unit includes:
A water softening device that continues the regeneration process when the ion concentration measured by the measurement unit is less than a predetermined reference value, and stops the regeneration process when it is equal to or higher than the reference value. The water softening device according to claim 1, wherein the reference value is an ion concentration at which a specific precipitate is generated due to a reaction between ions in the alkaline electrolyzed water and the hardness component. The water softening device according to claim 1, wherein the reference value is an ion concentration at which specific precipitates frequently occur due to a reaction between ions in the alkaline electrolyzed water and the hardness component. The water softening device according to claim 3, wherein the frequent occurrence is the occurrence of the specific precipitate when the pH of the alkaline electrolyzed water is 10.0 or higher. comprising a trapping part that traps precipitates caused by the hardness component,
The control unit includes:
The water softening device according to claim 1, wherein when the ion concentration measured by the measurement unit is equal to or higher than the reference value, feeding of the alkaline electrolyzed water to the capture unit is stopped. The control unit includes:
When the ion concentration measured by the measurement unit is equal to or higher than the reference value, a water softening tank drainage flow path including the water softening tank, the electrolytic tank, and a flow path communicating the soft water tank and the electrolytic tank. The water softening device according to claim 1 or 5, wherein the acidic electrolyzed water remaining in the water softening device is drained. The control unit includes:
When the ion concentration measured by the measurement unit is equal to or higher than the reference value, a neutralization tank including the neutralization tank, the electrolytic tank, and a flow path communicating the neutralization tank and the electrolytic tank. The water softening device according to claim 1 or 5, wherein alkaline electrolyzed water remaining in the drainage channel is drained. a flow rate measurement unit that measures the flow rate of water flowing into the neutralization tank;
a water softening tank drainage flow path including the water softening tank, the electrolytic tank, and a flow path communicating the soft water tank and the electrolytic tank;
a neutralization tank drainage flow path that includes the neutralization tank, the electrolytic tank, and a flow path that communicates the neutralization tank and the electrolytic tank;
Equipped with
The control unit includes:
a timer unit that measures the time required for draining the alkaline electrolyzed water;
a storage unit that stores a flow rate ratio of the softening tank drainage flow path and the neutralization tank drainage flow path;
a calculation unit that calculates the time required for draining the acidic electrolyzed water based on the measurement value of the flow rate measurement unit and the flow rate ratio,
The water softening device according to claim 1 or 5, wherein the acidic electrolyzed water is drained based on the time calculated by the calculation unit. The water softening device according to claim 2 or 3, wherein the specific precipitate is magnesium hydroxide.

Images